injury...strained or pulled glute or ham

Pulled my hamstring this summer, went away. 2moths later feels like pain in higher, can't do a leg swing, painful to stretch, painful to sit, cannot deadlift or do lunges, basically its killing my workouts... Anyone have advice of what it is and mainly what to do about it?

Any black and blue marks?
Does doing the "trigger points" in the glutes, maybe low back, hams and quads down thru and around the knees help?
Does "foam rolling" help?
A good "magnesium" supplement perhaps!?